Stepless variable transmission

ABSTRACT

An infinitely variable transmission has a pair of track members movable along separate paths which intersect one another. Each track member has a plurality of longitudinally spaced-apart elements projecting therefrom, the elements of one track member meshing with the elements of the other track member at the region of intersection. Each of the elements of one of the track members has dimensions which continuously vary from a point adjacent one edge toward the center of that track and from the base toward a free extremity of the respective element itself, to provide a surface along that element which is angled laterally to the edge of the track and transversely to the surface of the track from which that element projects. As the other track member is put in motion along its respective path, the elements projecting therefrom mesh with the elements projecting from the first track member along the region of intersection, and as a result of the configuration of each projecting element of the first track member, the motion imparted to that member is in the direction of its respective path. The depth of engagement of the elements in the region of intersection is selectively variable to control the relative extent of motion of the first track member as its elements are encountered by elements of the other track member. The elements on the other track members are guided to encounter the elements of the first track member at a consistent preselected point for a given extent of engagement between the elements, regardless of the extent of movement of either track member. The elements mesh by undergoing sliding contact with one another in the region of the intersection, and when in such sliding contact, the motion of the engaged elements is restricted to substantially longitudinal motion along the respective paths of the track members.

United States Patent Marcus 1 Mar. 7, 1972 [54] STEPLESS VARIABLE TRANSMISSION [72] Inventor: Ernst Marcus, Casilla 258, La Paz, Bolivia [22] Filed: Nov. 10, 1970 [21] Appl. No.: 88,421

[52] US. CL ..74/63, 74/1 74/84,

74/217 R [51] Int. Cl ..F16l1 21/12, Fl6h 27/04, Fl6h 9/00 [58] Field of Search ..74/2l7, l, 63, 84

[56] References Cited UNITED STATES PATENTS 3,491,603 1/1970 Harris ..74/63 Primary ExaminerLeonard H. Gerin Attomey-Brufsky, Staas, Breiner & Halsey ABSTRACT An infinitely variable transmission has a pair of track members movable along separate paths which intersect one another. Each track member has a plurality of longitudinally spacedapart elements projecting therefrom, the elements of one track member meshing with the elements of the other track member at the region of intersection. Each of the elements of one of the track members has dimensions which continuously vary from a point adjacent one edge toward the center of that track and from the base toward a free extremity of the respective element itself, to provide a surface along that element which is angled laterally to the edge of the track and transversely to the surface of the track from which that element projects. As the other track member is put in motion along its respective path, the elements projecting therefrom mesh with the elements projecting from the first track member along the region of intersection, and as a result of the configuration of each projecting element of the first track member, the motion imparted to that member is in the direction of its respective path. The depth of engagement of the elements in the region of intersection is selectively variable to control the relative extent of motion of the first track member as its elements are encountered by elements of the other track member. The elements on the other track members are guided to encounter the elements of the first track member at a consistent preselected point for a given extent of engagement between the elements, regardless of the extent of movement of either track member. The elements mesh by undergoing sliding contact with one another in the region of the intersection, and when in such sliding contact, the motion of the engaged elements is restricted to substantially longitudinal motion along the respective paths of the track members.

11 Claims, 5 Drawing Figures PATENTEDMAR 71972 3, 646 825 SHEET 1 [IF 2 I I l V Q l I", A r g N INVENTOR 23/ 2' ERNST MARCUS 2,1 31 MM; BY rdm Hal ATTORNEYS PAIENTEDMAR 7 I972 SHEET 2 [IF 2 I mvm'ron ERNST MARCUS Zmgsky items,

uawz ATTGRNEYS STEPLESS VARIABLE TRANSMISSION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to mechanical means for transmitting power, and more particularly to a power transmission mechanism which is infinitely variable to undergo a smooth transition from any given speed to any other given speed within the limitations of the mechanism.

2. Prior Art Attempts in the past to provide infinitely variable power transmission systems have been largely unsuccessful for a variety of reasons. Yet, new approaches are continually proposed because the provision of an efficient, relatively compact, and powerful stepless transmission would undoubtedly gain wide acceptance in motor vehicles and other forms of power-driven equipment. The shifting from one gear ratio to another, whether by manual or automatic means, in present day motor vehicle transmission system, for example, creates abrupt variations in the power delivered to the vehicle wheels. The result is undesirable strain in the nature of impact loading on transmission parts at each shift, and a noticeable absence of smoothness in ride to occupants of the vehicle.

SUMMARY OF THE INVENTION Briefly, according to the present invention, an infinitely variable transmission, that is, a stepless variable transmission, includes a pair of track-defining members which move longitudinally along predetermined differing paths. The path of one of the track members intersects the path of the other in such a way that one track member can be engaged with and disengaged from the other. The track members may constitute endless belts chains, gearwheels, or other like device provided with projecting elements to engage and mesh with the projecting elements of the other track member at a preselected zone or region of intersection.

One of the track members has uniformly spaced projecting elements each having dimensions which continuously vary from a point adjacent one edge of the track toward the center thereof and from the base of the respective element (i.e., the surface of the track) toward a free extremity thereof, so that one face of the element is angled laterally to the edge of the track and transversely to the surface of the track. That face angle, dimensions, and exposure are duplicated on each element projecting from the first track member, relative to that track. The other track member has projecting elements in the form of teeth which engage the projecting elements of the first track member to mesh therewith in the nature of a sliding contact between elements in the zone of path intersection. By ar ranging the tracks and the elements thereon in such a manner that the projecting elements on the other track member, which is the driving member, undergo successively greater interference with the angled face of the respective projecting elements on the first track member which is the driven member, as the former elements move longitudinally along their respective path, the force transmitted on the first track member cause it to move laterally with respect to the other track member. The relative movement depends on such factors as angle of intersection of the two track members and face angle of the elements.

The depth of engagement of the two sets of projecting elements is variable at will to control the speed of movement of the driven track member and to allow the speed to be varied smoothly and continuously within a preselected range. Means are provided to guide the elements of the driving track member into engagement in the preselected zone of intersection with the elements of the first track member at a consistent preselected point on each of the latter elements for a given depth of engagement. Further means are provided to restrict the motion of the engaged elements when in sliding contact with one another to longitudinal motion along the respective paths of the track members for those elements.

In a preferred embodiment of the invention, the driven track member is in the form of an endless belt with projecting elements in the form of uniformly spaced laterally extending teeth, each having a trapezoidal end surface adjacent to an edge of the belt and a rectangular end surface at the end of the tooth most remote from that edge. One face of the tooth then varies smoothly and continuously from one end surface to the other and from the base at which it is fastened to the surface of the belt to its free extremity. Guide plates for each tooth are provided on the endless belt. One plate is in abutment against the rectangular end surface of the respective tooth and the other is a continuation thereof except it is disposed at an angle thereto.

The other track member is, in the preferred embodiment, a pair of spaced parallel chains driven by a sprocket and having uniformly spaced bars extending laterally between the two chains and resiliently mounted to the chains to permit lateral motion in either direction relative to the longitudinal path of the latter track member. In the preferred embodiment of the invention disclosed, teeth are provided on this track member which are fastened in pairs at respective ends of each bar and are preferably pyramidal or conical in shape. The spacing between teethon a single bar is such that these teeth encounter successive guide plates for teeth on another track member at the same respective point. It will be understood of course, that there can be as many teeth along each bar as is necessary to handle theload on the transmission; the only limitation being that the spacing between the teeth be such that the teeth encounter successive guide plates for the teeth on the other track. During movement in the zone of intersection (i.e., the zone of engagement of the two sets of teeth) means on the bar cooperate with means on the overall housing of the transmission to restrict the teeth, and hence their respective track members, to longitudinal motion.

Accordingly, it is a principal object of the present invention to provide an improved stepless variable transmission.

It is another object of the invention to provide a stepless variable transmission which is strong, efficient, and relatively compact.

BRIEF DESCRIPTION OF THE DRAWINGS The above and still further objects, features, and advantages of the present invention will be most clearly understood by reference to the following detailed description of a preferred embodiment, especially when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary perspective view of the two tracks in a condition of partial engagement;

FIG. 2 is a fragmentary perspective view, partly in phantom, of the tracks in partial engagement, taken from a different viewpoint;

FIG. 3 is a perspective view of a channel member of the type used in the embodiment of FIGS. 1 and 2;

FIG. 4 is a fragmentary perspective view of a portion of the channel member of FIG. 3 together with a coupling and mounting structure for the channel member; and

FIG. 5 is a diagrammatic view of a part of the entire transmission system, viz, the driven track and its mountings, particularly illustrating the manner in which the depth of intersection of one track with the other can be adjusted to vary the output speed of the transmission.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to FIG. I, a first track member 10 in the form of an endless belt of flexible construction is arranged to undergo movement in upreselected direction indicated by the arrowhead adjacent one of its edges. A second track member 12 in a plane parallel to and spaced from the plane of belt 10 is provided in the form of a pair of parallel spaced-apart chains I3, 14 linked by bars 15 spaced uniformly apart along the Iongitudinal axis of the parallel chains. Only two such bars 15 are shown in FIG. 1 for the sake of clarity in depicting the relationship between the two track members and the elements thereon. It is to be understood, however, that the bars are spaced apart along the entire length of the chains of the track member 12. Preferably, tack member 12 is also of endless construction, and is arranged to move along a path in a direction perpendicular to the direction of movement of track member 10, as indicated by the arrowhead adjacent chain 14.

Track member 10, which will hereinafter sometimes be referred to as the driven member, has a set of arrays 16 of elements projecting from a surface directly opposite the surface of the other track member 12, hereinafter sometimes referred to as the driving member. Each of arrays 16 is composed, in the illustrative embodiment shown in FIG. 1, of three separate elements, two of which, 17 and 18, constitute plates of rectangular cross section and uniform thickness. The third projecting element 19 of each array 16 is of uniformly varying cross section from a rectangular end 20 to a trapezoidal end 21. The base of each projecting element 19, i.e., the side of the element which is secured to the flexible endless belt is also trapezoidal and the top surface may be slightly trapezoidal in shape as shown or may be entirely rectangular conforming in thickness to the thickness of end 20 of that element. Thus, the face 22 of each element 19 is angled laterally to the edge 23 of endless belt and is also angled transversely to the surface of the belt from which the element projects.

As described above, elements 17 and 18 are plates of uniform thickness, with element 18 constituting in essence an extension of element 19 at end 20 thereof, flush with the back surface of element 19. Guidance for the selection of location of plate 18 and of the length of that plate relative to the width of belt 10 will be set forth presently. Plate 17 is secured to the surface of belt 10 at an angle to the edge of the belt and to the other two elements of the respective array 16, for reasons which will be described. Plate 17 may extend to the edge of belt 10 opposite to edge 23 rather than to a point short of the opposite edge as shown in FIG. 1. Preferably however, plate 17 does not reach beyond the plane containing plate 18 of the next adjacent array 16 of projecting elements toward which plate 17 extends.

Bars are secured in bearings 25 fastened to appropriate links of chains 13 and 14, in such a manner as to be permitted to undergo lateral movement relative to the chains. That is to say, bars 15 are fastened to the chains to be in floating relationship therewith. This is readily accomplished by the use of the bearings 25 and of end-retained biasing springs on each bar. Mounted at an end of each bar 15 is a pointed element 26 which may be referred to as a blade, the end of the bar on which each blade 26 is mounted alternating with consecutive bars along the length of track member 12. A pair of channel members 27 are secured preferably resiliently to the transmission housing at either side of track member 12, on an interfering course with respect to the paths of the alternate endmounted blades 26. Each channel member 27 is composed of resiliently coupled halves, with the two halves together forming a slot or channel 28 through which a respective blade 26 may move as the track member 12 is advanced in the indicated direction of motion. The blades 26 and channel members 27 are provided to restrict the motion of teeth 30 carried by each bar to substantially longitudinal motion relative to track member 12 during movement along a specific portion of the zone or region of intersection of the two track members.

In particular, each bar 15 carries at least a pair of teeth 30, the teeth on any given bar 15 being spaced apart by a distance equal to the spacing longitudinally between successive arrays 16 of projecting elements on endless belt 10. The arrangement is such that when track member 12 moves in the direction of the arrow, the teeth 30 on any given bar 15 encounter angled plates 17 in consecutive arrays 16 of projecting elements on belt 10. Accordingly, teeth 30 undergo sliding contact with the respective plates 17 until they encounter plates 18 along which they also move as track member 12 moves, finally to engage projecting elements 19 in consecutive arrays 16 at the end 20 of each of those elements. Continued movement of track member 12 causes teeth 30 to transmit forces to projecting elements 19 as the teeth and the latter projecting elements interfere along the normal path of movement of track member 12. Since belt 10 is arranged to undergo movement, this interference between teeth and projecting elements 19 causes the belt to move in the direction indicated by the arrowhead, and the extent of that motion of the belt depends upon the depth of engagement of the teeth 30 and the projecting elements 19 because of the angle of face 22 varying with height.

The track member 12 is shown in FIG. 2 from a different angle of perspective with somewhat greater size and with only a portion of the track member 10, specifically two adjacent arrays 16 of projecting elements, shown in phantom for the sake of clarity. With concurrent reference to FIGS. 3 and 4, channel members 27 are mounted at either side of track member 12 to engage respective blades 26 at alternate ends of successive bars 15 as track member 12 undergoes longitudinal movement (with respect to its axis). Each channel member 27 includes in addition to its central channel 28 which is aligned parallel to the longitudinal axis of track member 12, a perpendicularly oriented slot 33 which opens into a countersunk or chamfered region 34 at face 35. Slot 33 accommodates a pair of rails 36 at either end thereof, the two rails being coupled by a bar 37 of hexagonal cross section which is intended to occupy the chamfered region 34. Face plates 38 (only those at the left-hand side of channel member 27 as viewed in FIG. 3 being shown, for the sake of clarity) are fastened to face 35 of channel members 27 to restrain bar 37 from movement away from slot 33. However, bar 37 and rails 36 are dimensioned such that channel member 27 would slide free thereof except for the presence of spring-mounted plates 39. Each of plates 39 fits into a respective further slot 40 oriented normal to slot 33, and is coupled to the slot-inserted end of the respective rail 36 by springs 41 (FIG. 4). Except for that coupling, each of plates 39 is free to move relative to rail 36 and bar 37. Accordingly, when the rail 36-bar 37 system is fastened in each respective channel member 27, the othenavise unconnected two halves of the channel member can undergo separation to the extent permitted by the compression of springs 41 at each end of slot 33. Such separation is shown to be occurring in the right-hand channel member 27 of FIG. 2, and is caused by the entry and interference of a respective blade 26 with slot 28 of the channel member, as will be described presently.

Each of rails 36 is mounted to a wall 42 (FIG. 2) of the housing for the transmission system, and each is spring loaded, in the nature of a shock absorber, to undergo reciprocating movement from a normal bias point at which respective channel member 27 intercepts a blade 26.

In operation, blade 26 enters channel slot 28 shortly before teeth 30 on its associated bar 15 meet plate 17. Channel 27 and bar 15 will then be moved together laterally by plate 17 till teeth 30 reach plate 18. Blade 26 will then force the two halves of channel 27 apart, as described heretofore till their respective upper and lower surfaces press against mating sur faces on the housing. Friction material is bonded to the channel surfaces and to mating surfaces on the housing, and channel 27 will thus be kept firmly in place against the housing. Channel slot 28 is now held captive and the continued movement of blade 26 and bar 15 is constrained to a linear path during contact with face 22 of element 19 imparting motion to track member 10.

Alternatively, blade 26 may comprise a block having grooved upper and lower surfaces mating with complemental surfaces on the bottom of upper part of channel member 27 and the top of the lower part of channel member 27. In this configuration, blade 26 will move freely relative to channel 27 while teeth 30 engage element 17. The two halves of element 27 are fixed to the housing and of sufficient width to accommodate blade 26 through the full range of the lateral displacement permitted to bar 15. In this configuration, blade 26 engages the two grooved guiding blocks 27 simultaneously or very shortly before teeth 30 engage element 19. Guiding plate 18 may be omitted. The engagement between the blade and guiding blocks ensures that teeth 30 and bar 15 are constrained to a linear path.

With specific reference to the channel member illustrated in FIG. 3, it will be observed that channel slot 28 of channel member 27 has a height dimension that varies with the length of the channel member. In particular, the length of the constricting portion 44 between wide portion 45 and narrow portion 46 of channel 28 is equal to the length of projecting element 18 encountered by tooth 30. Moreover, the constricting portion is positioned such that blade 26 enters and proceeds through that portion simultaneously with the movement of tooth 30 along the entire length of element 18. The narrow portion 46 of channel 28 corresponds in length and position (with respect to its penetration by blade 26) to the length and position of angled projecting element 19 (with respect to its sliding contact with tooth 30). Still another slot, 48, is provided in each channel member 27 (FIGS. 2 and 3) to accept that portion of each respective bar 15 adjacent blade 26, prior to separation of the halves of the channel member. To that end, the length of slot 48 is at least equal to the length of projecting element 17 measured in a direction parallel to the longitudinal axis of track member 12.

In operation of the stepless variable transmission, the two track members and 12 which are arranged and adapted to be movable relative to one another in a direction normal to the planes of both tracks to permit varying the depth of engagement of the teeth 30 and the arrays 16 of projecting elements, are initially positioned according to the desired speed or gear ratio when track movement is to begin. When teeth 30 are in contact with the uppermost zone of surface 22 of element 19, the surface of which zone is a continuation of plate 18 and at right angle to the edge of track 10, the transmission is in neutral. As track member 12 is driven in a direction indicated by the arrowhead adjacent chain 14 in FIG. 1, a tooth 30 encounters slanted projecting element 17 in a given array 16. The point at which this contact occurs on element 17 depends in part on the speed movement of the tracks. As a consequence, the element 17 forces the bar on which the respective contact tooth 30 is mounted, in a direction counter to the normal bias exerted by the end-retained biasing spring 29 to laterally move channel 27 until separation and immobilization of the element occurs as tooth 30 contacts element 18. As tooth 30 moves along projecting element 18, blade 26 enters and proceeds through the constricting portion 44 of channel 23 until, when the tooth engages end 20 of projecting element 19, the two halves of the channel member are separated and fixed to the transmission housing. The slot 28 is lubricated or its walls are coated with an appropriate substance such as Teflon (trademark of Dupont) to reduce any friction occurring during this interference with blade 26. Guiding plate 18 and channel slot region 44 should be kept as short as feasible.

At this point, the blade 26, and hence teeth 30 on the respective bar 15 are constrained to movement in a strictly longitudinal direction relative to track member 12, since the separated channel halves are immobilized. As each tooth 30 moves along sloped face 22 of a respective projecting element 19, the tooth now exerts a force on that element which causes belt 10 to move in a direction indicated by the arrowhead adjacent edge 23 in FIG. 1. The extend of movement of driven track member 10 relative to the movement of driving track member 12 depends upon the depth of engagement (or meshing) of teeth 30 and projecting elements 19. Clearly, this relative movement is greatest when the tooth 30 contacts face 22 of element 19 along the base of the element, and is smallest when tooth 30 contacts face 22 along the top of the projecting element. if the top surface of each element 19 is completely rectangular, there is no motion of belt 10 for tooth contact with face 22 immediately adjacent that top surface.

With specific reference to FIG. 5 a system for varying the depth of engagement of teeth 30 and the element 19 is shown. The height of element 19 with respect to tooth 30 is varied by raising and lowering the sprockets 51 on which track 10 moves, which are mounted on pillars 52. There are threads on each pillar 52 engaged by a nut 53. A notched belt or a chain 55 connect all four nuts 53. One nut has an external gear portion 60. A gear 56 engages that nut 53. Rotating gear 56, caused by a suitable control mechanism, will effect raising or lowering track 10. One of sprockets 51 can also serve as a power takeoff with a suitable connection.

Since the slope of face 22 of element 19 varies smoothly with height (and with length) of that element, any desired change in depth of engagement of the tooth 30 and element 19 can be effected without abrupt transition in the transmission ratio. Hence, the transmission is stepless, or infinitely variable. The coupling of an output (i.e., power takeoff) shaft or connection to a sprocket or roller of endless belt 10 (as shown in FIG. 5) permits a rotary drive to be supplied to appropriate elements via the transmission.

It is preferred that the combined length of projecting elements 17 and 18, measured perpendicular to an edge of track 10, be less than the length of projecting element 19 measured the same way. The distance between bars 15 should be equal to that length of projecting element 19.

While I have disclosed a preferred embodiment of my invention, it will be apparent to those of ordinary skill in the relevant art that variations in the structure specifically illustrated and described may be resorted to without departing from the spirit and scope of the invention, as defined in the following claims.

What is claimed is:

1. An infinitely variable transmission, comprising a first system for transmitting motion to an element along a first predetermined path, first system including first track means movable along said path, a plurality of first elements projecting from said track means for movement therewith,

a second system for transmitting motion to an element along a second predetermined path intersecting the first-named path, said second system including second track means movable along said second path, a plurality of second elements projecting from said second track means for movement therewith,

means for producing engagement and disengagement between the projecting elements on said first and second track means and for at will varying the extent of engagement of said elements,

one of said track means having spaced-apart elements whose dimensions vary continuously from a base line adjacent one edge toward the center of that track means and from the base toward a free extremity of the respective element, to provide a surface along said element which is angled laterally to said edge and transversely to the surface of that track means from which the elements project,

means for imparting motion to the other of said track means to transmit forces from the projecting elements thereon to respective projecting elements on said one track means with which they engage, whereby to produce movement of said one track means, the extent of such engagement and the speed of said other track means determining the speed of movement of said one track means,

means for guiding the projecting elements of said other track means laterally thereof to encounter respective projecting elements of said one track means at a consistent preselected point on the latter elements for a given extent of engagement between the respective elements, regardless of the extent of movement of said one track means, and

means for restricting the motion of the engaged elements when in sliding contact with one another to virtually iongitudinally motion along the respective paths of the track means for those elements.

2. The infinitely variable transmission according to claim 1, wherein said projecting elements of said other track means comprise teeth.

3. The infinitely variable transmission according to claim 1, wherein said means for at will varying the extent of engagement of the respective elements thereon comprises means for varying the depth of engagement of said elements from substantially complete engagement to virtual lack of engagement, and wherein said restricting means functions in the aforesaid manner regardless of the extent of such engagement.

4. The infinitely variable transmission according to claim 1, wherein said guiding means comprises means defining a path at least partly lateral to said predetermined path of said other track means, and means resiliently mounting the elements of said other track means thereto to permit lateral movement from and return to a preselected position.

5. The infinitely variable transmission according to claim 4, wherein said restricting means comprises means coupled to said resilient mounted means for rigidifying the resiliently mounted elements positionally relative to said other track means to constrain the movement of said resiliently mounted elements to said virtually longitudinal motion when said consistent preselected point is encountered.

6. An infinitely variable transmission, comprising first track means movable along a first predetermined path,

second track means movable along a second predetermined path oriented at an angle to said first path,

said first and second track means having confronting surfaces,

means on each of said surfaces for engagement at selectively variable depths of engagement with the engagement means on the other of said surfaces, to produce movement of said second track means in response to movement of said first track means, said engagement means on illeach of said track means being constructed and arranged to vary the distance through which said second track means moves according to said depth of engagement.

7. The infinitely variable transmission according to claim 6, wherein said angle between the first and second paths is 8. The infinitely variable transmission according to claim 7, wherein said engagement means on said first track means are movable laterally of said first path to compensate for variations in point of engagement with said engagement means on said second track means according to the speed of movement of said track means.

9. The infinitely variable transmission according to claim 8, wherein a portion of said engagement means on said second track means has a sloping surface with respect to said surface of said second track means, said surface also sloping with respect to the edge of said track means, and a further portion of said engagement means on said second track means is for guiding said engagement means on said first track means into sliding contact with said sloping surface.

10. The infinitely variable transmission according to claim 9, wherein is further provided means cooperating with a portion of said first track means for restricting the movement of said engagement means thereon to longitudinal motion along said first path during said sliding contact with said engagement means on said second track means.

11. The infinitely variable transmission according to claim 10, wherein said restricting means comprises means for locking said engagement means on said first track means against said lateral movement. 

1. An infinitely variable transmission, comprising a first system for transmitting motion to an element along a first predetermined path, first system including first track means movable along said path, a plurality of first elements projecting from said track means for movement therewith, a second system for transmitting motion to an element along a second predetermined path intersecting the first-named path, said second system including second track means movable along said second path, a plurality of second elements projecting from said second track means for movement therewith, means for producing engagement and disengagement between the projecting elements on said first and second track means and for at will varying the extent of engagement of said elements, one of said track means having spaced-apart elements whose dimensions vary continuously from a base line adjacent one edge toward the center of that track means and from the base toward a free extremity of the respective element, to provide a surface along said element which is angled laterally to said edge and transversely to the surface of that track means from which the elements project, means for imparting motion to the other of said track means to transmit forces from the projecting elements thereon to respective projecting elements on said one track means with which they engage, whereby to produce movement of said one track means, the extent of such engagement and the speed of said other track means determining the speed of movement of said one track means, means for guiding the projecting elements of said other track means laterally thereof to encounter respective projecting elements of said one track means at a consistent preselected point on the latter elements for a given extent of engagement between the respective elements, regardless of the extent of movement of said one track means, and means for restricting the motion of the engaged elements when in sliding contact with one another to virtually longitudinally motion along the respective paths of the track means for those elements.
 2. The infinitely variable transmission according to claim 1, wherein said projecting elements of said other track means comprise teeth.
 3. The infinitely variable transmission according to claim 1, wherein said means for at will varying the extent of engagement of the respective elements thereon comprises means for varying the depth of engagement of said elements from substantially complete engagement to virtual lack of engagement, and wherein said restricting means functions in the aforesaid manner regardless of the extent of such engagement.
 4. The infinitely variable transmission according to claim 1, wherein said guiding means comprises means defining a path at least partly lateral to said predetermined path of said other track means, and means resiliently mounting the elements of said other track means thereto to permit lateral movement from and return to a preselected position.
 5. The infinitely variable transmission according to claim 4, wherein said restricting means comprises means coupled to said resilient mounted means for rigidifying the resilIently mounted elements positionally relative to said other track means to constrain the movement of said resiliently mounted elements to said virtually longitudinal motion when said consistent preselected point is encountered.
 6. An infinitely variable transmission, comprising first track means movable along a first predetermined path, second track means movable along a second predetermined path oriented at an angle to said first path, said first and second track means having confronting surfaces, means on each of said surfaces for engagement at selectively variable depths of engagement with the engagement means on the other of said surfaces, to produce movement of said second track means in response to movement of said first track means, said engagement means on each of said track means being constructed and arranged to vary the distance through which said second track means moves according to said depth of engagement.
 7. The infinitely variable transmission according to claim 6, wherein said angle between the first and second paths is 90*.
 8. The infinitely variable transmission according to claim 7, wherein said engagement means on said first track means are movable laterally of said first path to compensate for variations in point of engagement with said engagement means on said second track means according to the speed of movement of said track means.
 9. The infinitely variable transmission according to claim 8, wherein a portion of said engagement means on said second track means has a sloping surface with respect to said surface of said second track means, said surface also sloping with respect to the edge of said track means, and a further portion of said engagement means on said second track means is for guiding said engagement means on said first track means into sliding contact with said sloping surface.
 10. The infinitely variable transmission according to claim 9, wherein is further provided means cooperating with a portion of said first track means for restricting the movement of said engagement means thereon to longitudinal motion along said first path during said sliding contact with said engagement means on said second track means.
 11. The infinitely variable transmission according to claim 10, wherein said restricting means comprises means for locking said engagement means on said first track means against said lateral movement. 